4. Discussion
The first consideration, concerning the forensic purposes of our study, is related to the usefulness of the presented method. We showed that it works better when you deal with sebaceous latent prints and when the paper was treated with ninhydrin,furthermore, in the last section, we verified that it works even when you deal with solutions for thermal paper. Moreover, we
found that the NIR luminescence of the fingermarks developed with the 1,2-indanedione or DFO can be exploited in order to reveal latent prints because of the different intensity of the
radiation emitted, respectively, by the background and by the fingermark itself. The chemical and physical properties of the thermal paper and of the fingermarks, widely exploited in
our study, do not represent a novelty. Nevertheless, the proposed method has never been proposed before and represents an interesting novel approach to the inspection of forensic evidences involving thermal paper.